$13\mathrm{.}26$

The built$-$up timber beam is subjected to a vertical shear of $1200lb.$ Knowing that the allowable shearing force in the nails is $75lb,$ determine the largest permissible spacing $s$ of the nails$\mathrm{.}13\mathrm{.}26$

The built$-$up timber beam is subjected to a vertical shear of $1200lb.$ Knowing that the allowable shearing force in the nails is $75lb,$ determine the largest permissible spacing $s$ of the nails.